21676623 has 4 divisors (see below), whose sum is σ = 28902168. Its totient is φ = 14451080.

The previous prime is 21676619. The next prime is 21676631. The reversal of 21676623 is 32667612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21676623 - 2² = 21676619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21676643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3612768 + ... + 3612773.

It is an arithmetic number, because the mean of its divisors is an integer number (7225542).

Almost surely, 2^21676623 is an apocalyptic number.

21676623 is a deficient number, since it is larger than the sum of its proper divisors (7225545).

21676623 is an equidigital number, since it uses as much as digits as its factorization.

21676623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7225544.

The product of its digits is 18144, while the sum is 33.

The square root of 21676623 is about 4655.8160401803. The cubic root of 21676623 is about 278.8242492255.

The spelling of 21676623 in words is "twenty-one million, six hundred seventy-six thousand, six hundred twenty-three".